Republican presidential candidates sparred on a variety of fronts last night in Sioux City, Iowa, in the last debate scheduled ahead of the Jan. 3 Iowa caucuses next month. But they found agreement on at least one issue: Construction of the Keystone XL oil pipeline should begin immediately.

Addressing different questions from a panel of Fox News moderators, former House Speaker Newt Gingrich of Georgia, former Utah Gov. Jon Huntsman and Rep. Michele Bachman of Minnesota recommended that the 1,700-mile oil pipeline be approved without delay.

The Obama administration has put off a decision on the proposed pipeline until after the 2012 elections while it studies alternative routes for the project, which would carry oil sands crude from Alberta to the Gulf Coast.

Gingrich addressed the issue first, condemning the Obama administration's threat to veto a House bill that ties fast-track approval of the pipeline to a continued payroll tax cut.

"The president of the United States cannot figure out, I'm using mild words here, it is utterly irrational to say I'm now going to veto a middle-class tax cut to protect left wing environmental extremists in San Francisco," Gingrich said.

The former speaker then referenced congressional attempts to reform the welfare system under then-President Clinton, who vetoed several versions of the bill when Gingrich ran the House, before it was signed into law. He suggested Congress should do the same with the Keystone XL proposal.

"I'd say to the president, 'You want to look like you are totally out of touch with the American people, be my guest, but I'm not backing down when we're right and you are totally wrong,'" Gingrich said.

Huntsman stressed that while a relationship with Canada is important, the United States must find alternative sources of energy, reiterating his desire to see increased natural gas usage.

"This is always going to be a balancing act," Huntsman said of environmental concerns, "but the job we've got to undertake as an American people is to fuel our future. We have no choice. Our economy has hit the wall."

"I want to get rid of that heroin-like addiction we have based on imported oil," he added.

Bachmann addressed the pipeline stating: "If I was president of the United States, I wouldn't have taken the decision President Obama did. His entire calculation was based on his re-election effort."

Bachmann asserted: "The radical environmentalists said to President Obama: You pass Keystone, we're not going to do your volunteer door-to-door work. That's what Barack Obama has done to this country. He's put his re-election over adding jobs and making the United States energy independent."

Ex-Massachusetts Gov. Mitt Romney did not address the Keystone XL pipeline by name but suggested that expanding domestic energy resources would be a primary source of job growth in the United States in the near future. His remarks were made in response to a question posed by a user of the micro-blogging site Twitter.

"We have extraordinary energy resources in our country: opening those up, our president holds them off, doesn't give them the permits to start drilling and start getting the natural gas and oil, those are some of the areas that are going to be extraordinarily powerful," Romney said.

Texas Gov. Rick Perry addressed whether his criticism of federal loans for alternative energy, such as those given to the now bankrupt solar firm Solyndra, was hypocritical because he has favored the creation of similar programs in the Lone Star State during his tenure as governor.

"It should be in the purview and the decisionmaking process of a state if they want to help put tax policies in place that makes them be more competitive," Perry said in defense of the program, noting it backed both oil and alternative fuels. "Government shouldn't be picking winners and losers from Washington, D.C. -- that's the difference."